I have been in a new home since Feb of this year. The toilets are Gerber K-11. Since Sept. we have had one or the other of two toilets back up about once every week. In reading your report, I would like to know what toilets have the largest opening for waste to go through. Is there one out there that is 3" and what is the normal opening. Are most toilets raw finishes through the waste water holes. Is there a toilet that has a finished, smooth ceramic all the way through the water line of the toilet (which would allow waste to slide through better). I need some facts to present to my builder or I will probably be stuck with these toilets until we re-sell the house, which could be soon, if we don't resolve the problem.